Are Clear Blue Tests accurate?


I’ve just done this test and it looks like a faint positive. However I’ve read that clear blue do give random positives. I only brought it as it was the only one in the pharmacy wtf? My period is due in 4/5 days but I’ve been having AF cramps all day which is unusual for me, I think I’m around 10/11 DPO. My first response test this morning was negative. I’m pretty skeptical that this is a true positive but your advice would be much appreciated x